Anyone banking on a big-win breakthrough in Wednesday’s nuclear talks with Iran will likely find themselves in the same boat as investors who bet on an instant surge in the Facebook stock price last week. If there’s value to be found in nuclear negotiations with Iran, then — like an investment in Facebook — it’s likely to emerge over time. And in both cases, even the long-term outcome remains uncertain.

After weeks of upbeat assessments, Western officials seemed to tamp down expectations ahead of the meeting that got underway in Baghdad on Wednesday. “If we talk substantively on elements of a deal and agree to meet again in three weeks, Baghdad will have been a success,” a senior U.S. official told al-Monitor on Monday. The spin ahead of the talks in recent weeks has been positive — almost too positive for diplomats, who naturally prefer diminished expectations. At home, Iran’s leaders are proclaiming a great victory in the willingness of Western powers to negotiate while Iran continues to enrich uranium, suggesting that they’re preparing their public for a compromised deal that will be sold as a great victory. The Western narrative paints Iran’s willingness to negotiate as a consequence of ever tightening economic sanctions, implying that such pressure must be maintained to curb its nuclear ambitions.

There are some positive signs: Sunday’s talks in Tehran between IAEA chief Yukiya Amano and Iran’s nuclear negotiator Saeed Jalili appear to have yielded an in-principle agreement, not yet inked or finalized, to expand the nuclear-watchdog agency’s access to sensitive sites in Iran. Amano, who has taken a tough line in dealing with Iran, was upbeat, expecting a signed agreement “quite soon.” But the IAEA talks are the undercard to the negotiations between Iran and the P5+1 (the U.S., France, Britain, Germany, Russia and China). Even if they improve the atmosphere for the Baghdad meeting, a breakdown between Iran and the P5+1 would likely imperil any progress made by the IAEA.

Then again, Wednesday’s talks in the Iraqi capital — a venue chosen by Iran — are not an all-or-nothing affair. Last weekend’s G-8 summit communique called on Iran to use the opportunity to engage “in detailed discussions about near-term, concrete steps that can, through a step-by-step approach based on reciprocity, lead toward a comprehensive negotiated solution, which restores international confidence that Iran’s nuclear program is exclusively peaceful.” In other words, the world powers see the Baghdad talks as part of a diplomatic process likely to unfold in the coming weeks, aimed at creating a sustainable momentum of concrete steps to peacefully resolve the standoff.

In Baghdad, the two sides will lay down their opening bids to define the sequence of reciprocal steps required to break the deadlock and create diplomatic momentum. And, obviously, they will present substantially different ideas of the steps each should take, and in what sequence. Bridging the gaps via workable interim proposals may take many more weeks or months of negotiation.

The immediate focus of the P5+1 appears to be on halting Iran’s enrichment of uranium to 20% purity, a process that is ostensibly undertaken to create fuel for a medical-research reactor in Tehran, but which is substantially closer to weapons-grade material, by measure of reprocessing time, than the 3.5% uranium Iran was enriching for reactor fuel. Western powers will reportedly call on Iran to verifiably halt 20% enrichment and ship abroad its stockpile of such for conversion into fuel rods (which are difficult to turn into weapons-grade material). They’ll specifically ask Iran to halt work at Fordow, the hardened facility built into a mountainside near Qom, where 20% enrichment has been under way since January. The site has been of particular concern to the Israelis, who fear it may be beyond the reach of their air force.

A number of senior Iranian officials, past and present, have indicated that Iran would be willing to do a deal over 20% enrichment, although whether and on what terms they’d meet all the demands laid out above remain to be seen. But what would Iran get in exchange for a deal to halt 20% enrichment? There lies the rub. Iranian leaders have made clear that Tehran sees the quid pro quo for doing so as an easing of sanctions, particularly the measures aimed at choking off Iran’s oil exports due to take effect on July 1. “If those sanctions kick in, why would Iran make a deal now?” Carnegie Endowment for International Peace analyst George Perkovich told NPR on Tuesday. “They won’t. I think they’d just say, Well, hell, if you’re going to punish us in any case, then why should I concede anything? So agreeing to suspend those sanctions will be a very important factor for Iran.” But U.S. officials are stressing that concessions on 20% enrichment won’t be sufficient to ease sanctions pressure. “Just hope the Iranians are not deluding themselves [that] they are going to get sanctions relief now,” said the U.S. official who spoke to al-Monitor. “That’s not going to happen at this stage.”

Sanctions have been Washington’s most important form of leverage over Iran, and it’s unlikely to trade them away in exchange for interim agreements this early in the game. The step-by-step reciprocity approach, fashioned originally by the Russians, would require that the two sides agree on verifiable steps to make such moves gradual, but political pressures are such that the Obama Administration may not have the flexibility it may need to openly ease sanctions. Many of the U.S. measures have been imposed by Congress, which takes a dim view of nuclear compromise with Iran. And trying to reverse any pressure on Iran in an election year may prove challenging, particularly when Israel’s leaders are openly skeptical of the diplomatic process.

Prime Minister Benjamin Netanyahu insists that the bottom line for success is nothing less than agreement on the dismantling of Iran’s uranium-enrichment capabilities, even to 3.5%. It’s highly unlikely that Iran would agree to give up its right as a nonproliferation-treaty signatory to enrich uranium for peaceful purposes, and it doesn’t appear that it’s being asked to do so by the P5+1. Still, expect Israel to push back fiercely against any move to relax sanctions pressure on Iran on the basis of interim agreements — and also to try to set deadlines on diplomacy lest the Iranians use the process to simply buy time.

European leaders and diplomats appear to be searching for mechanisms to bridge the gap between what Iran expects if it gives up 20% enrichment and what Obama will politically be able to give. There’s talk in Europe of delaying the implementation of some of the oil-related sanctions due to take effect in July, and allowing de facto work-arounds on some of the financial sanctions targeting Iran’s banking sector — all conditional on progress toward implementing confidence-building measures. But the E.U.’s consensus-based decisionmaking make that more difficult too.

Nobody is expecting a deal in Baghdad beyond another round of talks to be held within a matter of weeks. Nor are Western negotiators unaware of the pitfalls of an open-ended process that doesn’t substantially alter the status quo. The key to meaningful progress may depend less on trust and accord, as much as it will be based on the shared sense that the alternative to a peaceful solution may be too ghastly to contemplate.

Tony Karon is a senior editor at TIME, where he has covered international conflicts in the Middle East, Asia, and the Balkans since 1997. A native of South Africa, he now resides with his family in Brooklyn, New York.